Okay heres the situation, My mother bought her first mercedes (1980 280CE) from a neighbor for $800USD After spending 4 years without and climate control options (the top defroster button was the only working button on the whole unit) I decided to rip apart the dash. I found out that the defroster button happend to be the only button that was "ecetrically" connected the others had some sort of air hose system. I stopped there and gave up but I did try blowing into them and whatnot and starting up the car to see what woudl happen.....nothing happend. Now a year later the car becomes mine and I started researching the issue and found out that these controlls are run by vacuum! I've never seen this before? then again I'm only 17 So to make a long story short I now feel as if this could be a simple problem? Vacuum motor/pump? how could I pinpoint the malfunction? I know that you guys know what your talking about, and have the feeling you can help me out, this is probably a common problem. Thanks in advance!!

-Ben

Hi Ben,
Sorry to be the bearer of bad news, but it sounds like your car has the notoriously problematic Climate control II system. If it has a vertical row of buttons you've got it. You will find a servo unit under the hood on the passenger's side, a black cover is on top, and loads of vacuum hoses, wires and heater hoses are connected to it. If that's what you have, go to the unwired tools.com site and print off their vacuum hose diagrams for the climate control II system. The vacuum system must be in pristine condition, NO LEAKS at all, for the heater/AC to work properly. Once you've gotten rid of the vacuum leaks you may also have a defective servo unit. The unwired tools digital unit is the good fix for it, but some have found rebuilt units and successfully repaired their heaters.
Good luck with it!

__________________
Richard Wooldridge
'01 ML320
'82 300D 4.3L V6/T700R4 conversion
'82 380SL, '86 560SL engine/trans. installed
'79 450SL, digital servo update
'75 280C

WOW......talk about expensive However, I only need Heat, and AC no fine tuning adjustments that climate control offers. Is there a way I can bypass the vacuum tubes?? Im guessing that these vacuum hoses lead to a vacuum soleniod so-to-speak. Why couldent you convert these solenoids or just the ones to turn on the AC into a regular electronic solenoid? is this do-able? And yea the buttons are vertical and its the Climate Control II sys.
-Ben